221221222000 has 160 divisors (see below), whose sum is σ = 577420721280. Its totient is φ = 81722009600.

The previous prime is 221221221997. The next prime is 221221222031. The reversal of 221221222000 is 222122122.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1251084 + ... + 1416916.

It is an arithmetic number, because the mean of its divisors is an integer number (3608879508).

Almost surely, 2^221221222000 is an apocalyptic number.

221221222000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221221222000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288710360640).

221221222000 is an abundant number, since it is smaller than the sum of its proper divisors (356199499280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221222000 is a wasteful number, since it uses less digits than its factorization.

221221222000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165908 (or 165892 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 221221222000 its reverse (222122122), we get a palindrome (221443344122).

The spelling of 221221222000 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand".